Verrill, Lucy

2013-06-26T14:01:09Z

2013-06-26T14:01:09Z

2006

This thesis assesses the environmental marginality of a site at the Atlantic fringe of the British Isles, occupied at various points throughout prehistory. Palaeoclimatic proxy records from the North Atlantic show that climatic fluctuations have occurred in the mid- and late-Holocene, at amplitudes likely to be perceptible to human communities. Coincident environmental changes occurred to affect the development of landscapes via vegetation change and pedogenesis. The degree to which prehistoric agricultural economies were vulnerable to these external fluctuations is tested in this thesis. The archaeological complex at Belderg Beg, Co. Mayo, Ireland, consists of a sub-peat stone-built field system of the sixth millennium cal. BP, a Middle Bronze Age roundhouse and adjacent areas of ridge-andfurrow cultivation. By the time of Bronze Age occupation, blanket bog already covered a significant proportion of the landscape. A combination of on- and off-site investigation strategies included AMS 14C dated sediment stratigraphic analyses, palynology, soil micromorphology, peat humification and geochemistry. Results show that peat initiation occurred during Neolithic agricultural occupation, at c. 5465 cal. BP. The initial woodland assemblage was a combination of typical upland and lowland tree types, and had been subjected to disturbance. The economy was primarily pastoral but with an arable component. Abandonment occurred at c. 5375 cal. BP, and woodland regenerated rapidly. Neolithic abandonment occurred several centuries prior to the spread of blanket peat over the fields. Peat spread upslope at an average rate of c. O.385m/cal. yr. The Bronze Age archaeological remains probably represent several discrete phases of occupation, associated with intensive arable agriculture which included soil amendment strategies, and ceasing in the mid-second millennium cal. BP. Geochemical analysis failed to support previous hypotheses that a vein of copper ore 2km distant was exploited during the Bronze Age. The results from this investigation add to a growing corpus from western Ireland suggesting a clear pattern of Early and Middle Neolithic sedentism and mixed agriculture, followed by abandonment until reoccupation in the Early Bronze Age. As the Neolithic field system at Belderg Beg was apparently smaller and less regular than that at nearby Ceide Fields, it may represent an economically marginal site in terms of core-periphery relationships. Abandonment occurred during a phase of relative climatic aridity and it is concluded that soil deterioration and erosion was probably a factor in the demise of agriculture. The Bronze Age occupation is more difficult to characterise in terms of economy, but the gradual contraction of intensive agriculture suggests that again, soil quality rather than direct climatic shifts was the limiting factor and that the location eventually became environmentally marginal for an economy including significant cereal production.

536230

http://hdl.handle.net/1842/7285

eng

University of Edinburgh

History

Archaeology

Later prehistoric environmental maginality in western Ireland: multi-proxy investigations

PhD Doctor of Philosophy